1. Field of the Invention
The present invention relates to the field of data storage on magnetic media.
2. Description of Related Art
Data is stored on magnetic media by writing on the magnetic media using a write head. Magnetic media can be formed in any number of ways, such as tape, floppy diskette, and hard disk. Writing involves storing a data bit by utilizing magnetic flux to set the magnetic moment of a particular area on the magnetic media. The state of the magnetic moment is later read, using a read head, to retrieve the stored information.
Data density is determined by the amount of data stored on an area of magnetic media and depends on how much area must be allocated to each bit. Data on magnetic media is often stored in a line or track. Magnetic media often have multiple tracks. In the case of the disk, the tracks are nested annular rings. More bits per ring and more rings per disk increases data density. Data density, therefore, is determined not only by the bit length, but also by the width of the bit which determines the track width.
Data density is controlled by controlling the magnetic flux generated between poles of the write head. Typically write heads do not contact the magnetic media but instead are separated from the magnetic media by a layer of air or air bearing. The magnetic flux generated between the poles acts across the air bearing to change the magnetic moment of an area on the magnetic media.
To decrease bit size, small read and write heads, such as thin film heads, are constructed. Thin film heads commonly employ separate write and read heads. Thin film heads are typically formed by depositing and etching layers of magnetic, non-magnetic, dielectric, and electrically conductive materials. The structure of the heads are defined by selectively exposing photoresist to control where etching and deposition occurs.
Selective exposure commonly employs masks or reticles to control the exposure. Unexposed photoresist is removed so that the surface or layer below may be selectively etched to form the head structure. A significant problem with current thin film head structures and manufacturing techniques, however, is that they have limitations to improving data density. The present invention provides an improved thin film head design and improved production methods which allows for improved data density.